Transit passenger vehicles licensed, where required, and maintained for regular use, including spares and vehicles out of service for maintenance purposes, but excluding vehicles in "dead" storage, leased to other operators, in energy contingency reserve status, permanently not usable for transit service, and new vehicles not yet outfitted for active service. (APTA1)

The following video provides you with the correct English pronunciation of the word "Active Vehicle", to help you become a better English speaker.